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authorDouglas Anderson <dianders@chromium.org>2019-12-19 01:35:28 +0300
committerNeil Armstrong <narmstrong@baylibre.com>2020-02-13 12:22:05 +0300
commit3438ea3dc89603bd83819cd254acc32a50526497 (patch)
tree7cde2f900d2333d400a50dbf2366643d574e50ff /drivers/gpu
parent37c1d89820e77dae525d33e8f20cf85442c2b55a (diff)
downloadlinux-3438ea3dc89603bd83819cd254acc32a50526497.tar.xz
drm/bridge: ti-sn65dsi86: Group DP link training bits in a function
We'll re-organize the ti_sn_bridge_enable() function a bit to group together all the parts relating to link training and split them into a sub-function. This is not intended to have any functional change and is in preparation for trying link training several times at different rates. One small side effect here is that if link training fails we'll now leave the DP PLL disabled, but that seems like a sane thing to do. Signed-off-by: Douglas Anderson <dianders@chromium.org> Tested-by: Rob Clark <robdclark@gmail.com> Reviewed-by: Rob Clark <robdclark@gmail.com> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191218143416.v3.7.I1fc75ad11db9048ef08cfe1ab7322753d9a219c7@changeid
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/bridge/ti-sn65dsi86.c86
1 files changed, 52 insertions, 34 deletions
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index ea57778b93d0..47b1948a1dcf 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -530,6 +530,46 @@ static unsigned int ti_sn_get_max_lanes(struct ti_sn_bridge *pdata)
return data & DP_LANE_COUNT_MASK;
}
+static int ti_sn_link_training(struct ti_sn_bridge *pdata)
+{
+ unsigned int val;
+ int ret;
+
+ /* set dp clk frequency value */
+ ti_sn_bridge_set_dp_rate(pdata);
+
+ /* enable DP PLL */
+ regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
+
+ ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
+ val & DPPLL_SRC_DP_PLL_LOCK, 1000,
+ 50 * 1000);
+ if (ret) {
+ DRM_ERROR("DP_PLL_LOCK polling failed (%d)\n", ret);
+ goto exit;
+ }
+
+ /* Semi auto link training mode */
+ regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
+ ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val,
+ val == ML_TX_MAIN_LINK_OFF ||
+ val == ML_TX_NORMAL_MODE, 1000,
+ 500 * 1000);
+ if (ret) {
+ DRM_ERROR("Training complete polling failed (%d)\n", ret);
+ } else if (val == ML_TX_MAIN_LINK_OFF) {
+ DRM_ERROR("Link training failed, link is off\n");
+ ret = -EIO;
+ }
+
+exit:
+ /* Disable the PLL if we failed */
+ if (ret)
+ regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
+
+ return ret;
+}
+
static void ti_sn_bridge_enable(struct drm_bridge *bridge)
{
struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
@@ -555,29 +595,8 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge)
regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG,
CHA_DSI_LANES_MASK, val);
- /* Set the DP output format (18 bpp or 24 bpp) */
- val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0;
- regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
-
- /* DP lane config */
- val = DP_NUM_LANES(min(pdata->dp_lanes, 3));
- regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
- val);
-
- /* set dsi/dp clk frequency value */
+ /* set dsi clk frequency value */
ti_sn_bridge_set_dsi_rate(pdata);
- ti_sn_bridge_set_dp_rate(pdata);
-
- /* enable DP PLL */
- regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
-
- ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
- val & DPPLL_SRC_DP_PLL_LOCK, 1000,
- 50 * 1000);
- if (ret) {
- DRM_ERROR("DP_PLL_LOCK polling failed (%d)\n", ret);
- return;
- }
/**
* The SN65DSI86 only supports ASSR Display Authentication method and
@@ -588,19 +607,18 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge)
drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET,
DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
- /* Semi auto link training mode */
- regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
- ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val,
- val == ML_TX_MAIN_LINK_OFF ||
- val == ML_TX_NORMAL_MODE, 1000,
- 500 * 1000);
- if (ret) {
- DRM_ERROR("Training complete polling failed (%d)\n", ret);
- return;
- } else if (val == ML_TX_MAIN_LINK_OFF) {
- DRM_ERROR("Link training failed, link is off\n");
+ /* Set the DP output format (18 bpp or 24 bpp) */
+ val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0;
+ regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
+
+ /* DP lane config */
+ val = DP_NUM_LANES(min(pdata->dp_lanes, 3));
+ regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
+ val);
+
+ ret = ti_sn_link_training(pdata);
+ if (ret)
return;
- }
/* config video parameters */
ti_sn_bridge_set_video_timings(pdata);